As recent improvement in standard of living has led to growing demand for a pleasant life, acoustic design for buildings becomes important. Currently, soundproofing panels having sound absorption capability so as to absorb a variety of interior noise are used as interior materials for buildings. Moreover, a variety of sound absorption sheets and sound absorption type soundproofing panels including the sound absorption sheets are used in fields that require a soundproofing capability, such as interior and exterior materials for car seats.
A sound absorption sheet generally requires permeability and sound absorption capability in order to minimize noise, and requires excellent permeability in order to maximize sound absorption effects. Thus, the sound absorption sheet requires a number of perforations to block noise.
Generally, in order to use a sound absorption material, a surface decorative material is formed on an outer surface of the sound absorption material, thereby causing a problem of severe deterioration in soundproofing or fireproofing performance of the sound absorption material. Korean Patent Publication No. 10-2011-0065877 discloses an acoustic panel system including a perforated sheet formed with plural minute perforations, but does not disclose improvement in decorative performance by realizing a variety of shapes on an external surface of the perforated sheet.